From 1951—“Piercing the Unknown”, IBM Mainframe Scientific Computers

The computer shown in this vintage film, whose model number is never given, was announced to the public on 1952-05-21 as the IBM 701 Electronic Data Processing Machine. This was IBM’s first production electronic scientific computer and their first mainframe computer. The project to develop it was funded by the U.S. National Security Agency (NSA) and was called the “Defense Calculator” during the development phase and only renamed the 701 after IBM received permission to market it commercially. A total of 19 IBM 701s were eventually sold, and it was the first of the 700/7000 series of vacuum tube computers (700) and subsequent 7000 series transistorised machines.

The 701 used electrostatic storage Williams tubes for its main memory, providing total memory of 2048 36-bit words, which allowed computation in either 18- or 36-bit signed magnitude fixed point arithmetic. A high speed fixed head magnetic drum was available to expand storage capacity, and up to ten magnetic tape drives could be attached. Punched card input and output and printed output were provided by peripherals adapted from earlier IBM tabulating and calculator equipment.

Customers were mostly in the U.S. defense racket, with a few exceptions such as the U.S. Weather Bureau, General Motors, and DuPont Research.